Final answer:
Slab pull and ridge push are two forces that contribute to plate motion. Slab pull appears to contribute more to plate motion.
Step-by-step explanation:
Slab pull and ridge push are two forces that contribute to plate motion. Slab pull is the force created by the sinking of a subducted plate, while ridge push is the force generated by the upwelling of magma at mid-ocean ridges. Slab pull appears to contribute more to plate motion.